Oki ES 1624n MFP - Manual (Page 144)

Windows: Black Printing • 144
Windows
Black Printing _________________
Normally, the printer will print black using all four toner colors. If you
are doing a lot of black-only printing, you can set the printer to use
only black toner.
To Select Black Printing for a Particular Job in the PCL Driver:
Click Grayscale on the driver’s Color tab as you print the job:
To Select Black Printing for a Particular Job in the Postscript Driver,
Windows XP, 2000 and NT 4.0 Only:
Select Print in Greyscale under Color Control Method on the Color
tab as you print the job: